Adventure Time—the lovable, adventurous Cartoon Network series penned by mastermind artist and writer Pen Ward—has blown up to staggering popularity. Search for the show and its characters online and you'll find a mess of fan-made renditions and mash-ups and even new inventions (like the currently non-existent baby product of Jake—a dog who can stretch to any shape or length—and his girlfriend, the rainbow-colored Lady Rainicorn).

But it's not the fan art and bubbling fandom that made Pen Ward realize just how popular the show had gotten. When I asked him during a phone interview last week, he said it was seeing his characters in one of those toy vending machines:

Sometimes I have to go to meetings where I get shown toys, t-shirts and merchandise. Things that Cartoon Network is overseeing that's being made. The thing that hit me the most was when I was looking at those little toys that appear in bubbles in quarter machines, those little plastic bubbles with toys in them. Looking at t-shirts and other things didn't hit me as hard but when I saw those vending machine toys and realized that people might spend quarters on Adventure Time toys in those little machines, that struck a chord with me. Because as a kid you love those things. It hit a soft, sweet spot in my mind. In my childhood memories. That's when it hit me.

Pen Ward is also a huge video game fan. It's reflected in the show—most notably with BMO, an adorable and versatile game system and friend to Finn and Jake—as well as in Ward himself. So was the show getting picked up for a game equally exciting to Ward? Was this another reinforcing, ego-boosting, momentous occasion as seeing tiny plastic bubbles filled with Jakes and Finns was?

Not...quite.

A game is a different feeling. Because I love games as an adult. A game just feels like a challenge to me. When Adventure Time got picked up I wasn't excited as much as I was telling myself, "Ok, now I'm going to have to buckle down and work incredibly hard and not sleep and make sure this is as good as I can make it. It's more about anticipating a big, heavy task. That's what a game feels like to me.

When I asked him if writing for the show was just as nerve-wracking, he professed that both writing for the show and game required the same amount of his attention. But then, that seems to be the way Pen Ward works. He doesn't seem to have the heart to let Finn and Jake down, in much the same way that the dynamic duo is in the show.